Diagnostic Table
WARNING: This page is about a different variant/trim than selected.
- Refer to the chart below.
High (Discharge) Pressure Low (Suction) Pressure Component - Causes High or Clutch Cycling High Condenser - inadequate airflow. High Normal to High Engine - overheating. Normal to High Normal Refrigerant overcharge - air in refrigerant. Normal to Low Normal to High A/C suction line - partially restricted or plugged.(1) Normal to Low Low or Clutch Cycling Low refrigerant charge, A/C suction line - partially restricted or plugged A/C evaporator discharge air temperature sensor - reading erratic or low (if equipped).(2) Erratic Operation or Compressor Not Running A/C evaporator discharge air temperature sensor - poor connection at A/C clutch connector or A/C evaporator discharge air temperature sensor connector. A/C electrical circuit erratic - see the appropriate A/C Electrical Circuit Wiring Diagram. Refer to AUTOMATIC CLIMATE CONTROL SYSTEM . Normal to Low High Compressor - low performance. Additional Possible Cause Components Associated With Inadequate Compressor Operation - Compressor Drive Belt - loose
- Compressor Clutch - slipping
- Clutch Coil Open - shorted, or loose mounting
- Control Assembly Switch - dirty contacts or sticking open
- Clutch Wiring Circuit - high resistance, open or blown fuse
- Compressor Operation Interrupted by Engine Computer
Additional Possible Cause Components Associated With a Damaged Compressor - Incorrect Clutch Air-gap
- Refrigerant Leaks
(1) Low pressure reading will be normal to high if restriction is downstream of service access valve. (2) Low pressure reading will be low if pressure is taken near the compressor and restriction is upstream of service access valve.
NOTE:
The following table is used to guide diagnosis of the refrigerant system if operating pressures are outside normal limits.